These are the results of my April, 2019 Federal Census for federal membership on LinkedIn: 2,191,819 civilian and DOD (including uniformed services) members on LinkedIn. This is an increase of 170,209 over 2018, 8% growth in one year.
I have included direct links to cabinet departments and a few other major activities.
I have included direct links to cabinet departments and a few other major activities.
A couple of caveats: 
1) I may have overlooked some sub-agency level activities, often because I could not find them (if you find something i missed, please let me know); 
2) I have included three non-executive branch activities (USPS, LOC and GAO);
3) There is liable to be some contractors in these counts; 
4) I will update this list as I identify omissions;
5) Sorry about the alignment. This is cut and paste from Word;
6) See Total Federal Employment estimates at the bottom of this post.
My unscientific study of job functions indicates 15%+ of the feds & DOD employees on LinkedIn have an IT-related job title.
Send me an email if you'd like to discuss this or my LinkedIn training programs: markamtower@gmail.com or go to the on demand version of LinkedIn for GovCon
4) I will update this list as I identify omissions;
5) Sorry about the alignment. This is cut and paste from Word;
6) See Total Federal Employment estimates at the bottom of this post.
My unscientific study of job functions indicates 15%+ of the feds & DOD employees on LinkedIn have an IT-related job title.
Send me an email if you'd like to discuss this or my LinkedIn training programs: markamtower@gmail.com or go to the on demand version of LinkedIn for GovCon
DOD and Military Agency member counts on LinkedIn
DOD & Military
US Army                                                        366,985
          Army Natl Guard                                    43,963
          US Army Reserve                                   18,965
          Network Enterprise Tech Cmmd              6,836
          Corps of Engineers                                 20,370
          CCDC Army Research Lab                        535
          USA CCDC                                                208
USA CCDC C5ISR 41
C5ISR CENTER - NVESD 62
USA CCDC C5ISR 41
C5ISR CENTER - NVESD 62
          USA ERDC                                                485
          USA CERDEC                                            33
          Army Rapid Capabilities *RCCTO)           44
          USA Acq Support Ctr                                 70
          USA Contracting Command                  2,458
          USA Cyber Command                              532
US Army Special Warfare Center (SWC) 78
US Army Special Warfare Center (SWC) 78
          Army Special Forces (Airborne)               652
Army Special Ops Command 288
Army Futures Command 396
Army Special Ops Command 288
Army Futures Command 396
Total for US Army:                                     514,234
US Air Force HQ                                        229,853
          Air Natl Guard                                       6,299
          USAF Reserve                                     15,971
          Air National Guard Recruiting`             6,301
          USAF Research Lab                              2,234
          USAF Space Command                        1,684
          USAF Special Ops Cmmd                      572
          AF Ofc of Special Investigations            347
AF Ofc of Scientific Research 81
AF Air Cmmd & Staff College 452
AF SBIR/STTR 48
AF Ofc of Scientific Research 81
AF Air Cmmd & Staff College 452
AF SBIR/STTR 48
Total for USAF:                                        263.842
US Navy HQ                                             206,067
          USN Reserve                                     13,139
          NAVSEA                                             4,139
          NAVAIR                                              3,259
          SPAWAR                                             4,652
          Ofc of Naval Research                           421
          Ofc of Naval Intel                                  133
NAWCAD 967
NAWCAD 967
          Naval Surface Warfare Ctr                  1,569
Naval Surf Wrfr Ctr Dahlgren 531
Naval Surf Wrfr Ctr Crane 291
Naval Undersea Wardfare Center 438
Naval Surf Wrfr Ctr Dahlgren 531
Naval Surf Wrfr Ctr Crane 291
Naval Undersea Wardfare Center 438
          Naval Surface Warfare Ctr (MD)           572
          Naval Surface Warfare Ctr (Phil)           344
Naval Surface Warfare Ctr (Corona) 197
NAWCAD 881
Military Sealift Command 4,468
Naval Surface Warfare Ctr (Corona) 197
NAWCAD 881
Military Sealift Command 4,468
Total for USN:                                         237,600
US Marine Corps                                           39,990
          USSOCOM                                          1,770
          JSOC                                                         91
          DTRA                                                   1,286 
DLA 7,228
DLA 7,228
          DCMA                                                  5,708
          DIA                                                       2,946
Def CounterIntel & Sec Agency 281
Def Security Cooperation Agency 254
Defense Security Service 716
Def CounterIntel & Sec Agency 281
Def Security Cooperation Agency 254
Defense Security Service 716
          DCAA                                                2,337                   
          DAU                                                        755
          DFAS                                                    7,251         
          Missile Def Agency                              1,453
          National Guard Bureau                         2.067         
          DHA                                                        928
          Tricare                                                     458
          Wash HQ Svcs                                        355
          Natl Geospatial-Intelligence Agcy       2,351
          NSA                                                      1,163
          DARPA                                                   507
          Am Battle Monuments Comm                109
          Ofc of Chairman, JCS                             232
          JCS Staff                                               1,074
          DoDEA                                                 2,595
Def Innovative Unit 94
Def Innovative Unit 94
Total for DOD:                                            97,270
DOD AND UNIFORMED SERVICES TOTAL        1,151,699
USDA HQ                                                  18,682
          NRCS                                                 4,414
          FS                                                     17,888       
          ARS                                                    5,277
          APHIS                                                1,888
          FSIS                                                    2,448         
          FAS                                                     322
          Natl Inst of Food and Ag                    213
Natl Organic Program 97
Natl Organic Program 97
          AMS                                                   148
          NAL                                                     27
Rural Development 625
Rural Development 625
USDA total:                                              52,029
CIA                                                             1,091
Commerce HQ                                           2,682
          NOAA                                               6,082
          Census                                               7,405
          BEA                                                     369
          ITA                                                    1,401
          NTIS                                                      11
          NTIA                                                   203
          EDA                                                     270
          MBDA                                                   85
          NIST                                                 3,634
Total for Commerce:                               22,142
Corp for Natl & Community Svc          721
CPSC                                                             349
Consumer Financial Protection Bureau      1,292
Education                                                  10,910
EEOC                                                         1,505
Energy                                                       5,095
          Bonneville                                        2,214         
          Sandia                                               8,207
          Berkeley                                           3,728
          Oak Ridge                                        3,636
          Argonne                                            3,841
          Los Alamos                                      8,180
          Pacific NW                                       3,653
          Idaho National Lab                          1,623
          National Renewable Energy Lab     2,157         
          Western Area Power Admin            864
          National Nuclear Security Admin   833
          Oak Ridge National Laboratory      3,789
Lawrence Livermore 6,122
FermiLab 1,698
Brookhaven 2,445
Lawrence Livermore 6,122
FermiLab 1,698
Brookhaven 2,445
Total for Energy:                                     57,923
EPA                                                            11,316
Exec Office of the President                          243
          EOP/White House                               164
          Natl Security Council                           114
          US Digital Service                              153
Ex-Im Bank                                                   552
Farm Credit Admin                                       279
FDIC                                                          5,318
FEC                                                               293
FERC                                                         1,288
FLRA                                                           106
Fed Mine Safety                                            48
Federal Reserve System 2,812
Federal Reserve System 2,812
Federal Reserve Board                               2,176
FRB- NY 3,016
FRB- Chicago 1,418
FRB- SF 1,470
FRB- Dallas 914
FRB - Atlanta 1,229
FRB - Boston 967
FRB -Richmond 1,239
FRB- St Louis 1,141
FRB - KC 1,447
FRB - Minneapolis 802
FRB TOTAL 18,361
FRB- NY 3,016
FRB- Chicago 1,418
FRB- SF 1,470
FRB- Dallas 914
FRB - Atlanta 1,229
FRB - Boston 967
FRB -Richmond 1,239
FRB- St Louis 1,141
FRB - KC 1,447
FRB - Minneapolis 802
FRB TOTAL 18,361
GAO*                                                         21,733
GSA                                                           11,740
          NIH                                                  22,474
          NCI                                                   3,998
          CDC                                                 15,292
         FDA                                                  14,466       
          CMS                                                 3,366
          HRSA                                               1,215
          SAMHSA                                         338
          Ag for Healthcare Research             451
          NIMH                                               715
          NIDA                                                255
          Admin for Community Living           80
          IHS                                                   5,103
PHS 1,180
PHS 1,180
Total for HHS:                                         79,960
Homeland Security HQ                           32,801
          ICE                                                     1,149
          FEMA                                              13,090
          US Coast Guard                               25,309
US Coast Guard Auxiliary 590
US Coast Guard Auxiliary 590
          CBP                                                   7,059
          TSA                                                  11,620
          US Secret Service                              1,482
          FLETC                                                  141
CISA 300
CISA 300
Total for DHS:                                          93,541
HUD                                                          6,380
Interior HQ                                              3,210
          FWS                                                 5,205
          NPS                                                11,122
          BLM                                                5,699
          USGS                                              6,475
          BIA                                                 1,564
          Reclamation                                    3,098
          Ocean Energy Mgmt                          369
BSEE 308
BSEE 308
Total for Interior:                                   37,050
International Trade Commission                 356
Justice HQ                                               15,731
          BOP                                                  1,675
          Criminal Div                                    1,078
          US Attorneys Ofc                             5,405
          US Marshall’s Service                         451
          DEA                                                  2,114
          FBI                                                    8,023
          ATF                                                   1,722          
Total for Justice:                                     36,199
Labor HQ                                                 7,007
          BLS                                                  1,845
OSHA 262
OSHA 262
Total for Labor:                                       9,114
Library of Congress*                                 3,387
NARA                                                        1,536
          Ames                                                2,580
Goddard 4,179
Goddard 4,179
          Glenn                                                1,601
          JPL                                                   6,837
          Langley                                            1,662
Total for NASA:                                       48,750
National Gallery of Art                              876
NEA                                                           171
NEH                                                           159
NRC                                                           2,344
NTSB                                                         338
Office of Govt Ethics                                  38
OMB                                                          512
OPIC                                                          587
OPM                                                           3,482
Peace Corps                                               9,597
PBGC                                                         1,013
US Postal Service                                      149,831
USPS OIG                                                  16,442
Railroad Retirement Board                          567
SBA                                                            3,779
SEC                                                            3,559
Smithsonian                                               4,349
SSA                                                            39,380
State Department                                     29,421
TVA                                                           8,993
US Trade Rep                                            242
          FAA                                                  28,068       
          FHA                                                   1,925
          FTA                                                      376
          FRA                                                      574
          FHWA National Highway Inst             153
Volpe 320
Volpe 320
Total for Transportation:                        35,444
Treasury HQ                                            9.021
          BEP                                                    750
          IRS                                                26,886
          OCC                                                3,231
          Mint                                                   558
Total for Treasury:                               40,446
Veterans Affairs                                       102,246
VOA                                                           1,824
CIVILIAN AGENCY TOTAL                1,001,045
Miscellaneous* 40,000
* These are Miscellaneous listed as “US Government," "US Govt" and "US Govt DoD).      
Estimated total             2,192,219
- The miscellaneous "US government" listing has been used by government employees for well over 10 years. It was used prior to 2010 because there was no Federal endorsement or policy for using social media, so employees did not want to name their respective agencies. It is also used by those in the IC to mask their agencies.
 
Total Federal Employment
Labor Department 2018 Total Federal Jobs Estimate: 2,797,000
OPM Total Civilian Employment (excluding USPS): 2,059,605
Civilian Full Time and Permanent: 1,837,622
Other Civilian Employment: 221,983
Postal Service Employment: 603,911
Active Duty Military: 1,345,550
National Guard / Reserve Forces: 802,842
OPM Total Civilian Employment (excluding USPS): 2,059,605
Civilian Full Time and Permanent: 1,837,622
Other Civilian Employment: 221,983
Postal Service Employment: 603,911
Active Duty Military: 1,345,550
National Guard / Reserve Forces: 802,842
Copyright 2019, Mark Amtower