Convert to ICD-10-CM: 
309.9 converts approximately to:
- 2015/16 ICD-10-CM F43.20 Adjustment disorder, unspecified
 ICD-9-CM Volume 2 Index entries containing back-references to 
309.9:
- Adaptation reaction (see also Reaction, adjustment) 309.9
- Crisis emotional NEC 309.29 emotional NEC 309.29   acute reaction to stress 308.0 acute reaction to stress 308.0 
  adjustment reaction 309.9 adjustment reaction 309.9
  specific to childhood or adolescence 313.9 specific to childhood or adolescence 313.9 
 
 
- Disorder - see also Disease adjustment (see also Reaction, adjustment) 309.9 adjustment (see also Reaction, adjustment) 309.9  with with   anxiety 309.24 anxiety 309.24 
   anxiety and depressed mood 309.28 anxiety and depressed mood 309.28 
   depressed mood 309.0 depressed mood 309.0 
   disturbance of conduct 309.3 disturbance of conduct 309.3 
   disturbance of emotions and conduct 309.4 disturbance of emotions and conduct 309.4 
 
 
 
- Disturbance - see also Disease situational (transient) (see also Reaction, adjustment) 309.9 situational (transient) (see also Reaction, adjustment) 309.9
 
- Maladjustment simple, adult (see also Reaction, adjustment) 309.9 simple, adult (see also Reaction, adjustment) 309.9
  situational acute (see also Reaction, adjustment) 309.9 situational acute (see also Reaction, adjustment) 309.9
 
- Reaction acute situational maladjustment (see also Reaction, adjustment) 309.9 acute situational maladjustment (see also Reaction, adjustment) 309.9
  adaptation (see also Reaction, adjustment) 309.9 adaptation (see also Reaction, adjustment) 309.9
  adjustment 309.9 adjustment 309.9  with with   anxious mood 309.24 anxious mood 309.24 
   conduct disturbance 309.3 conduct disturbance 309.3     combined with disturbance of emotions 309.4 combined with disturbance of emotions 309.4 
 
   depressed mood 309.0 depressed mood 309.0 
   elective mutism 309.83 elective mutism 309.83 
   mixed emotions and conduct 309.4 mixed emotions and conduct 309.4 
   mutism, elective 309.83 mutism, elective 309.83 
   physical symptoms 309.82 physical symptoms 309.82 
   predominant disturbance (of) predominant disturbance (of)
   specific academic or work inhibition 309.23 specific academic or work inhibition 309.23 
   withdrawal 309.83 withdrawal 309.83 
 
  depressive 309.0 depressive 309.0 
  specified type NEC 309.89 specified type NEC 309.89 
 
  situational (see also Reaction, adjustment) 309.9 situational (see also Reaction, adjustment) 309.9  acute, to stress 308.3 acute, to stress 308.3 
  adjustment (see also Reaction, adjustment) 309.9 adjustment (see also Reaction, adjustment) 309.9
 
 
- Situational disturbance (transient) (see also Reaction, adjustment) 309.9 disturbance (transient) (see also Reaction, adjustment) 309.9
  maladjustment, acute (see also Reaction, adjustment) 309.9 maladjustment, acute (see also Reaction, adjustment) 309.9
  reaction (see also Reaction, adjustment) 309.9 reaction (see also Reaction, adjustment) 309.9