diff --git a/backend/tests/fixtures/minimal_837p.txt b/backend/tests/fixtures/minimal_837p.txt
new file mode 100644
index 0000000..6e19e83
--- /dev/null
+++ b/backend/tests/fixtures/minimal_837p.txt
@@ -0,0 +1,30 @@
+ISA*00*          *00*          *ZZ*11525703       *ZZ*COMEDASSISTPROG*260611*0814*^*00501*991102977*1*P*:~
+GS*HC*11525703*COMEDASSISTPROG*20260611*081417*991102977*X*005010X222A1~
+ST*837*991102977*005010X222A1~
+BHT*0019*00*ref-001*20260611*081417*CH~
+NM1*41*2*Test Submitter*****46*11525703~
+PER*IC*Test Contact*EM*test@example.com~
+NM1*40*2*COLORADO MEDICAL ASSISTANCE PROGRAM*****46*COMEDASSISTPROG~
+HL*1**20*1~
+PRV*BI*PXC*251E00000X~
+NM1*85*2*Test Provider Inc*****XX*1234567890~
+N3*123 Test St~
+N4*Denver*CO*80202~
+REF*EI*123456789~
+HL*2*1*22*0~
+SBR*P*18*******MC~
+NM1*IL*1*Doe*John****MI*ABC123~
+N3*456 Member St~
+N4*Denver*CO*80203~
+DMG*D8*19800101*M~
+NM1*PR*2*COHCPF*****PI*SKCO0~
+CLM*CLM001*100.00***12:B:1*Y*A*Y*Y~
+REF*G1*PA123~
+HI*ABK:Z00~
+LX*1~
+SV1*HC:99213*100.00*UN*1***1~
+DTP*472*D8*20260611~
+REF*6R*REF001~
+SE*26*991102977~
+GE*1*991102977~
+IEA*1*991102977~
\ No newline at end of file